Monolithic integration of GaN-based micromechanical resonators and HEMTs for timing applications

A platform for intimate integration of high-frequency gallium nitride (GaN) micromechanical resonators and AlGaN/GaN high electron mobility transistors (HEMTs) is reported. For the first time, cascade of a two-port GaN bulk acoustic resonator and AlGaN/GaN HEMT was co-fabricated on a silicon substrate. A high quality factor (Q) of 7413 is reported for a GaN contour-mode resonator at the resonance frequency of 119.8 MHz. More than 30 dB of signal tuning was achieved by using integrated HEMT for signal readout and amplification at the resonator output.